Pathogenicity of Aspergillus westerdijkiae to females and oothecae of Periplaneta Americana

ABSTRACT: Cockroach control is performed by the application of chemical insecticides which exert high selective pressure on populations and introduces synthetic substances in the environment, motivating the search for other methods of control such as entomopathogenic fungi. The objectives of this study were to investigate the pathogenicity of the JAB 42 Aspergillus westerdijkiae to females and oothecae of Periplaneta americana and to demonstrate its mechanism of action on oothecae. Suspensions containing 106 to 108 conidia/ml were used to infect females and oothecae. Mortality and other variables such as scanning electron microscopy were used to demonstrate the mechanism of action of the fungus. The isolated JAB 42 A. westerdijkiae is pathogenic to oothecae of P. americana, with low capacity to kill females. Adhesion, germination, penetration and extrusion of the fungus on the cockroach oothecae were observed.

RESUMO: O controle de baratas realizado através da aplicação de inseticidas químicos exerce alta pressão seletiva sobre as populações e introduz substâncias sintéticas no ambiente, motivando a procura por outros métodos de controle, como os fungos entomopatogênicos. Os objetivos deste trabalho foram investigar a patogenicidade do isolado JAB 42 de Aspergillus westerdijkiae a fêmeas e ootecas de Periplaneta americana e demonstrar o mecanismo de ação sobre ootecas. Suspensões contendo 106 a 108 conídios/mL do isolado foram usadas para infectar fêmeas e ootecas. A ação do fungo foi analisada pela mortalidade e outras variáveis, e por microscopia eletrônica de varredura. O isolado JAB 42 de A. westerdijkiae é patogênico a ootecas de P. americana, tendo baixa capacidade de matar fêmeas. Foi observada a adesão, germinação, penetração e extrusão do fungo sobre ootecas da barata.

Pathogenicity of Aspergillus westerdijkiae to females and oothecae of Periplaneta Americana

ABSTRACT: Cockroach control is performed by the application of chemical insecticides which exert high selective pressure on populations and introduces synthetic substances in the environment, motivating the search for other methods of control such as entomopathogenic fungi. The objectives of this study were to investigate the pathogenicity of the JAB 42 Aspergillus westerdijkiae to females and oothecae of Periplaneta americana and to demonstrate its mechanism of action on oothecae. Suspensions containing 106 to 108 conidia/ml were used to infect females and oothecae. Mortality and other variables such as scanning electron microscopy were used to demonstrate the mechanism of action of the fungus. The isolated JAB 42 A. westerdijkiae is pathogenic to oothecae of P. americana, with low capacity to kill females. Adhesion, germination, penetration and extrusion of the fungus on the cockroach oothecae were observed.

RESUMO: O controle de baratas realizado através da aplicação de inseticidas químicos exerce alta pressão seletiva sobre as populações e introduz substâncias sintéticas no ambiente, motivando a procura por outros métodos de controle, como os fungos entomopatogênicos. Os objetivos deste trabalho foram investigar a patogenicidade do isolado JAB 42 de Aspergillus westerdijkiae a fêmeas e ootecas de Periplaneta americana e demonstrar o mecanismo de ação sobre ootecas. Suspensões contendo 106 a 108 conídios/mL do isolado foram usadas para infectar fêmeas e ootecas. A ação do fungo foi analisada pela mortalidade e outras variáveis, e por microscopia eletrônica de varredura. O isolado JAB 42 de A. westerdijkiae é patogênico a ootecas de P. americana, tendo baixa capacidade de matar fêmeas. Foi observada a adesão, germinação, penetração e extrusão do fungo sobre ootecas da barata.

Pathogenicity of Aspergillus westerdijkiae to females and oothecae of Periplaneta Americana / Patogenicidade de isolado de Aspergillus westerdijkiae a fêmeas e ootecas de Periplaneta americana

Cockroach control is performed by the application of chemical insecticides which exert high selective pressure on populations and introduces synthetic substances in the environment, motivating the search for other methods of control such as entomopathogenic fungi. The objectives of this study were to investigate the pathogenicity of the JAB 42 Aspergillus westerdijkiae to females and oothecae of Periplaneta americana and to demonstrate its mechanism of action on oothecae. Suspensions containing 106 to 108 conidia/ml were used to infect females and oothecae. Mortality and other variables such as scanning electron microscopy were used to demonstrate the mechanism of action of the fungus. The isolated JAB 42 A. westerdijkiae is pathogenic to oothecae of P. americana, with low capacity to kill females. Adhesion, germination, penetration and extrusion of the fungus on the cockroach oothecae were observed.(AU)

O controle de baratas realizado através da aplicação de inseticidas químicos exerce alta pressão seletiva sobre as populações e introduz substâncias sintéticas no ambiente, motivando a procura por outros métodos de controle, como os fungos entomopatogênicos. Os objetivos deste trabalho foram investigar a patogenicidade do isolado JAB 42 de Aspergillus westerdijkiae a fêmeas e ootecas de Periplaneta americana e demonstrar o mecanismo de ação sobre ootecas. Suspensões contendo 106 a 108 conídios/mL do isolado foram usadas para infectar fêmeas e ootecas. A ação do fungo foi analisada pela mortalidade e outras variáveis, e por microscopia eletrônica de varredura. O isolado JAB 42 de A. westerdijkiae é patogênico a ootecas de P. americana, tendo baixa capacidade de matar fêmeas. Foi observada a adesão, germinação, penetração e extrusão do fungo sobre ootecas da barata.(AU)

Atividade ovicida in vitro de Pleurotus ostreatus var. florida SOBRE Ancylostoma sp. e Toxocara canis

Os animais de companhia são acometidos por uma infinidade de afecções parasitárias. Dentre elas se destacam as infecções causadas por ancilostomídeos e ascarídeos, pois estes, são responsáveis por uma alta taxa de mortalidade de cães e gatos, principalmente na fase inicial de vida. Além disso, parasitos do gênero Toxocara e Ancylostoma apresentam grande importância médico veterinária, pois são agentes das zoonoses Larva migrans visceral e Larva migrans cutânea respectivamente. Muitas pesquisas estão sendo desenvolvidas com intuito de minimizar os danos associados a estes parasitos, contudo, uma área ainda pouco explorada é relacionada a produtos naturais. Os fungos do gênero Pleurotus são bastante requisitados no mercado internacional tendo aplicações gastronômicas e medicinais, entretanto suas atividades nematicidas sobre nematoides de carnívoros ainda não foi relatada. Em busca disso, aproximadamente 1000 ovos de Ancylostoma sp. foram vertidos em placas de cultura de 6 poços, e em cada placa foi aplicada uma solução com diferentes concentrações do extrato aquoso de Pleurotus ostreatus var. florida (50mg/ml, 25 mg/ml, 12,5 mg/ml, 6,25 mg/ml, 3,12 mg/ml). As placas foram incubadas por 48h a 26ºC, e após o período, a leitura de eclosão de larvas foi realizada. No segundo experimento 1000 ovos de Toxocara canis foram vertidos em placas de cultura de 6 poços, e aplicada as mesmas concentrações anteriores do extrato aquoso e incubadas a 26º C por 21 dias. A cada 7 dias foram realizadas leituras em microscópio invertido para classificação da evolução embrionário dos ovos. Em ambos experimentos o controle negativo foi composto apenas de solução com ovos e água destilada. Foram realizadas triplicatas em todos os grupos de cada teste. No teste com Ancylostoma sp., houve um percentual de redução de eclodibilidade de no 67,16% em relação ao controle, tendo a concentração de 3,12% o maior percentual de eclodibilidade de larvas dentre as concentrações testadas. Já o ensaio experimental com ovos de Toxocara canis, todos as concentrações foram eficazes na diminuição de ovos larvados a partir do décimo quarto dia de avaliações. O Pleurotus ostreatus var. florida mostrou possuir uma boa atividade ovicida tanto sobre ovos de Ancylostoma spp., quanto sobre ovos de T. canis, demonstrando um grande potencial na utilização como controle biológico do nematódeos.

Companion animals are plagued by a multitude of parasitic diseases. Among them are the infections caused by hookworms and ascarids, as these are responsible for a high death rate of dogs and cats, especially in the initial phase of life. In addition, parasites of the genus Toxacara and Ancylostoma present great veterinary medical importance, as they are agents of zoonoses "Larva migrans visceral" and "Larva migrans cutaneum", respectively. Many researches are being developed in order to minimize the damages associated with these parasites, however, an area not yet explored is related to natural products. The fungi of the genus Pleurotus are highly requested in the international market, with gastronomic and medicinal applications, but their nematicidal activities on carnivorous nematodes have not yet been reported. In search of this, approximately 1000 eggs of Ancylostoma spp. were poured into 6-well culture plates, and a solution with different concentrations of the aqueous extract of Pleurotus ostreatus var. florida (50%, 25%, 12.5%, 6.25%, 3.12%). The plates were incubated for 48 h at 26 ° C, and after the period, larval hatching was performed. In the second experiment 1,000 Toxocara canis eggs were poured into 6-well culture plates and the same concentrations of the aqueous extract were applied and incubated at 26 ° C for 21 days. Every 7 days, the egg embryo evolution was classified. In both experiments the negative control was composed only of solution with eggs and distilled water. Triplicates were performed in all groups of each test. In the test with Ancylostoma spp., There was a percentage of reduction of hatchability up to 67.16% in relation to the control, and the concentration of 3.12% was the highest percentage of hatchability of larvae among the tested concentrations. In the experimental trial with Toxocara canis eggs, all concentrations were effective in the reduction of larval eggs from the fourteenth day of evaluations. Pleurotus ostreatus var. florida showed to have a good ovicidal activity both on Ancylostoma spp. eggs and on Toxocara canis eggs, demonstrating a great potential in the biological control of the nematode.

Ação de inseticidas sobre os ovos e lagartas da broca-pequena-dofruto do tomate, em bioensaio de laboratório / Action of insecticides on the eggs and larvae of the borer small-fruit tomato in laboratory bioassay

A broca-pequena-do-fruto é praga-chave na cultura do tomate por causar danos significativos às partes reprodutivas. Devido a isto, foi objetivo deste trabalho avaliar a eficiência de inseticidas sobre ovos e lagartas recém-emergidas, com e sem a adição de óleo vegetal (0,25%), em bioensaios de laboratório. Frutos com ovos foram coletados em cultivo de tomate estaqueado na quinzena posterior à última aplicação de agrotóxicos, sendo selecionados os frutos com ovos de coloração variável de branco a marrom claro, com 1 e 4 dias de incubação, e imersos em 1 L da calda inseticida por 5 segundos. O delineamento estatístico utilizado foi o inteiramente casualizado, com média de 18 frutos nos tratamentos e de, aproximadamente, 4 ovos/fruto. A avaliação da ação inseticida de 24 produtos foi realizada após a imersão na calda inseticida, observando-se, sob microscópio estereoscópico, os ovos quanto à integridade do córion, textura e coloração, lagartas emergidas, bem como os orifícios de entrada e de saída das larvas (aos 7 e 21 dias). Os produtos testados diferiram da testemunha quanto à densidade de lagartas eclodidas, bem como quanto à redução populacional de lagartas, podendo-se destacar Trebon 100 SC (etofenprox; 200 mL do produto comercial/100 L), Lannate BR (methomil; 100 mL), Thiobel 500 (cartap; 250 g) e Vertimec 18 CE (abamectin; 100 mL). A adição de óleo vegetal resultou em incremento na eficiência dos produtos.

Action of insecticides on tomato fruit borer eggs and larvae using laboratory bioassay. The tomato fruit borer is a key tomato pest in light of its damages to the plants’ reproductive parts. Therefore, the present study was aimed to evaluate the effectiveness of insecticides on the eggs and newly hatched larvae, when applied alone or associated with vegetable oil (0.25%), in laboratory bioassays. Fruits with eggs were collected in staked tomato crops fifteen days after the last application of agro-chemicals, selecting the fruits with eggs colored from white to light brown, which had between 1 and 4 days of incubation, followed by immersion of the fruit for 5 seconds in 1 L of the insecticide solutions. The experimental design was completely randomized, with an average of 18 fruits per treatment (24 insecticides and a control) and about 4 eggs per fruit. The evaluations were performed 7 and 21 days after immersion, using a stereomicroscope to observe the corion integrity, egg color, number of larvae emerged, and larvae fruit holes (entry and exit). The insecticides differed significantly from the control, most notably Trebon SC 100 (etofenprox; 200 mL of the commercial product/100 L), Lannate BR (methomil; 100 mL), Thiobel 500 (cartap; 250 g) and Vertimec 18 CE (abamectin; 100 mL). The addition of vegetable oil increased the insecticides’ effectiveness.

Ação de inseticidas sobre os ovos e lagartas da broca-pequena-dofruto do tomate, em bioensaio de laboratório / Action of insecticides on the eggs and larvae of the borer small-fruit tomato in laboratory bioassay

A broca-pequena-do-fruto é praga-chave na cultura do tomate por causar danos significativos às partes reprodutivas. Devido a isto, foi objetivo deste trabalho avaliar a eficiência de inseticidas sobre ovos e lagartas recém-emergidas, com e sem a adição de óleo vegetal (0,25%), em bioensaios de laboratório. Frutos com ovos foram coletados em cultivo de tomate estaqueado na quinzena posterior à última aplicação de agrotóxicos, sendo selecionados os frutos com ovos de coloração variável de branco a marrom claro, com 1 e 4 dias de incubação, e imersos em 1 L da calda inseticida por 5 segundos. O delineamento estatístico utilizado foi o inteiramente casualizado, com média de 18 frutos nos tratamentos e de, aproximadamente, 4 ovos/fruto. A avaliação da ação inseticida de 24 produtos foi realizada após a imersão na calda inseticida, observando-se, sob microscópio estereoscópico, os ovos quanto à integridade do córion, textura e coloração, lagartas emergidas, bem como os orifícios de entrada e de saída das larvas (aos 7 e 21 dias). Os produtos testados diferiram da testemunha quanto à densidade de lagartas eclodidas, bem como quanto à redução populacional de lagartas, podendo-se destacar Trebon 100 SC (etofenprox; 200 mL do produto comercial/100 L), Lannate BR (methomil; 100 mL), Thiobel 500 (cartap; 250 g) e Vertimec 18 CE (abamectin; 100 mL). A adição de óleo vegetal resultou em incremento na eficiência dos produtos. (AU)

Action of insecticides on tomato fruit borer eggs and larvae using laboratory bioassay. The tomato fruit borer is a key tomato pest in light of its damages to the plants reproductive parts. Therefore, the present study was aimed to evaluate the effectiveness of insecticides on the eggs and newly hatched larvae, when applied alone or associated with vegetable oil (0.25%), in laboratory bioassays. Fruits with eggs were collected in staked tomato crops fifteen days after the last application of agro-chemicals, selecting the fruits with eggs colored from white to light brown, which had between 1 and 4 days of incubation, followed by immersion of the fruit for 5 seconds in 1 L of the insecticide solutions. The experimental design was completely randomized, with an average of 18 fruits per treatment (24 insecticides and a control) and about 4 eggs per fruit. The evaluations were performed 7 and 21 days after immersion, using a stereomicroscope to observe the corion integrity, egg color, number of larvae emerged, and larvae fruit holes (entry and exit). The insecticides differed significantly from the control, most notably Trebon SC 100 (etofenprox; 200 mL of the commercial product/100 L), Lannate BR (methomil; 100 mL), Thiobel 500 (cartap; 250 g) and Vertimec 18 CE (abamectin; 100 mL). The addition of vegetable oil increased the insecticides effectiveness. (AU)

The influence of thymol+DMSO on survival, growth and reproduction of Bradybaena similaris (Mollusca: Bradybaenidae)

Bradybaena similaris (Férussac, 1821), commonly known as the Asian trampsnail, is a terrestrial snail native to Asia, introduced in other regions of the world. In Brazil, populations of this land snail are distributed from the state of Amapá in the North to Rio Grande do Sul in the South. This species acts as an intermediate host for parasites and is a difficult-to-control agricultural pest as well, causing great losses to crops and ornamental plant cultivation. This land snail is easily reared in the laboratory and has been successfully used as a biological model in studies that aim at verifying molluscicidal effects of plant extracts. Several studies have demonstrated that B. similaris, like many other species of land and freshwater snails, is physiologically adapted to survival over transitory unfavorable environmental conditions. Moreover, this species seems to have a life history strategy characterized by a short life span and a maximal opportunistic reproductive effort during transient favorable periods. Such biological features may potentially lead to the inefficacy of control attempts and, simultaneously, make this species able to repopulate sites previously treated with biocides. For this reason, studies that aim at verifying the effect of molluscicides on the reproduction, growth and survival of molluscs are greatly required. Molluscicides of plant origin may represent a safe and effective way of controlling these animals. Thymol is a substance of plant origin which has bactericidal, fungicidal and anti-inflammatory properties and has been presented as a promissory biocide of mollusc species. The aim of this work was to assess the molluscicidal property of thymol in combination with DMSO against eggs and adults of B. similaris. During 120 days, we evaluated the effect of thymol+DMSO at different concentrations (2.5 g/L and 5 g/L) on the hatching success, hatchling survival, growth and reproduction of B. similaris under laboratory conditions. We tested thymol+DMSO on 160 eggs, 160 10-day-old and 160 30-day-old juveniles. The results showed that thymol+DMSO (5 g/L and 2.5 g/L) affected hatching success, acting as an ovicide. The tests with 10-day-old juveniles showed that thymol+DMSO at 2.5 g/L and 5 g/L caused 90 and 100% of mortality, respectively. For the 30-day-old juveniles, thymol+DMSO caused 87.5% of mortality at 5 g/L, and 75% at 2.5 g/L. With regard to growth, the results were not significant. The 10-day-old individuals treated with thymol+DMSO showed only one reproductive event during the 120 days of the experiment. Thymol+DMSO showed molluscicidal and residual activity, which makes evident its potential for controlling snails, and consequently, snail-borne diseases.

The influence of thymol+DMSO on survival, growth and reproduction of Bradybaena similaris (Mollusca: Bradybaenidae)

Bradybaena similaris (Férussac, 1821), commonly known as the Asian trampsnail, is a terrestrial snail native to Asia, introduced in other regions of the world. In Brazil, populations of this land snail are distributed from the state of Amapá in the North to Rio Grande do Sul in the South. This species acts as an intermediate host for parasites and is a difficult-to-control agricultural pest as well, causing great losses to crops and ornamental plant cultivation. This land snail is easily reared in the laboratory and has been successfully used as a biological model in studies that aim at verifying molluscicidal effects of plant extracts. Several studies have demonstrated that B. similaris, like many other species of land and freshwater snails, is physiologically adapted to survival over transitory unfavorable environmental conditions. Moreover, this species seems to have a life history strategy characterized by a short life span and a maximal opportunistic reproductive effort during transient favorable periods. Such biological features may potentially lead to the inefficacy of control attempts and, simultaneously, make this species able to repopulate sites previously treated with biocides. For this reason, studies that aim at verifying the effect of molluscicides on the reproduction, growth and survival of molluscs are greatly required. Molluscicides of plant origin may represent a safe and effective way of controlling these animals. Thymol is a substance of plant origin which has bactericidal, fungicidal and anti-inflammatory properties and has been presented as a promissory biocide of mollusc species. The aim of this work was to assess the molluscicidal property of thymol in combination with DMSO against eggs and adults of B. similaris. During 120 days, we evaluated the effect of thymol+DMSO at different concentrations (2.5 g/L and 5 g/L) on the hatching success, hatchling survival, growth and reproduction of B. similaris under laboratory conditions. We tested thymol+DMSO on 160 eggs, 160 10-day-old and 160 30-day-old juveniles. The results showed that thymol+DMSO (5 g/L and 2.5 g/L) affected hatching success, acting as an ovicide. The tests with 10-day-old juveniles showed that thymol+DMSO at 2.5 g/L and 5 g/L caused 90 and 100% of mortality, respectively. For the 30-day-old juveniles, thymol+DMSO caused 87.5% of mortality at 5 g/L, and 75% at 2.5 g/L. With regard to growth, the results were not significant. The 10-day-old individuals treated with thymol+DMSO showed only one reproductive event during the 120 days of the experiment. Thymol+DMSO showed molluscicidal and residual activity, which makes evident its potential for controlling snails, and consequently, snail-borne diseases.

The influence of thymol+DMSO on survival, growth and reproduction of Bradybaena similaris (Mollusca: Bradybaenidae)

Bradybaena similaris (Férussac, 1821), commonly known as the Asian trampsnail, is a terrestrial snail native to Asia, introduced in other regions of the world. In Brazil, populations of this land snail are distributed from the state of Amapá in the North to Rio Grande do Sul in the South. This species acts as an intermediate host for parasites and is a difficult-to-control agricultural pest as well, causing great losses to crops and ornamental plant cultivation. This land snail is easily reared in the laboratory and has been successfully used as a biological model in studies that aim at verifying molluscicidal effects of plant extracts. Several studies have demonstrated that B. similaris, like many other species of land and freshwater snails, is physiologically adapted to survival over transitory unfavorable environmental conditions. Moreover, this species seems to have a life history strategy characterized by a short life span and a maximal opportunistic reproductive effort during transient favorable periods. Such biological features may potentially lead to the inefficacy of control attempts and, simultaneously, make this species able to repopulate sites previously treated with biocides. For this reason, studies that aim at verifying the effect of molluscicides on the reproduction, growth and survival of molluscs are greatly required. Molluscicides of plant origin may represent a safe and effective way of controlling these animals. Thymol is a substance of plant origin which has bactericidal, fungicidal and anti-inflammatory properties and has been presented as a promissory biocide of mollusc species. The aim of this work was to assess the molluscicidal property of thymol in combination with DMSO against eggs and adults of B. similaris. During 120 days, we evaluated the effect of thymol+DMSO at different concentrations (2.5 g/L and 5 g/L) on the hatching success, hatchling survival, growth and reproduction of B. similaris under laboratory conditions. We tested thymol+DMSO on 160 eggs, 160 10-day-old and 160 30-day-old juveniles. The results showed that thymol+DMSO (5 g/L and 2.5 g/L) affected hatching success, acting as an ovicide. The tests with 10-day-old juveniles showed that thymol+DMSO at 2.5 g/L and 5 g/L caused 90 and 100% of mortality, respectively. For the 30-day-old juveniles, thymol+DMSO caused 87.5% of mortality at 5 g/L, and 75% at 2.5 g/L. With regard to growth, the results were not significant. The 10-day-old individuals treated with thymol+DMSO showed only one reproductive event during the 120 days of the experiment. Thymol+DMSO showed molluscicidal and residual activity, which makes evident its potential for controlling snails, and consequently, snail-borne diseases.

Resistência de genótipos de Vigna unguiculata L. (Walp.) e eficiência de óleo de nim em Bemisia tabaci (Genn., 1889) biótipo B (Hemiptera: Aleyrodidae)

Dentre os fatores que podem afetar a produtividade de feijão caupi detaca-se o ataque de Bemisia tabaci (Gennadius, 1889) biótipo B. Dessa forma, o objetivo desse trabalho foi avaliar a resistência de feijão caupi associado a doses de nim no desenvolvimento e oviposição de mosca branca. Os experimentos foram conduzidos em casa de vegetação no Departamento de Fitossanidade da Faculdade de Ciências Agrárias e Veterinárias, UNESP/Câmpus de Jaboticabal-SP, no período de outubro de 2009 a agosto 2010. Foram realizados testes para oviposição, com e sem chance de escolha, antibiose e ação ovicida. Para identificar os tipos de resistência avaliou-se sete genótipos de Vigna unguiculata L. (Walp.), BRS Milênio, BR17 Gurguéia, BR3 Tracuateua, BRS Novaera, Sempre Verde, BRS Urubuquara e IPA-206. De acordo com os dados obtidos pode-se concluir que os genótipos BRS Urubuquara, IPA-206 e BR17 Gurgueia apresentaram resistência do tipo não preferência para oviposição de B. tabaci biótipo B; o genótipo BRS Urubuquara apresenta resistência do tipo não preferência para alimentação e/ou antibiose; o genótipo Sempre Verde foi o mais suscetível; e, B. tabaci biótipo B prefere ovipositar na face abaxial das folhas na posição superior das plantas de caupi. Posteriormente, foram selecionados dois genótipos resistentes e um suscetível ao ataque de mosca branca, os quais foram associados a diferentes doses de produto natural a base de óleo de nim, sendo realizados testes de não preferência para oviposição, antiobiose e ação ovicida. De acordo com os dados obtidos pode-se concluir o genótipo BRS Urubuquara e IPA-206 associados ou não ao óleo de nim foram os menos ovipositados por B. tabaci biótipo B; a associação do óleo de nim com o genótipo Sempre Verde reduziu a oviposição do inseto; a posição superior das folhas na planta é a mais ovipositada pela praga...

Amongst the factors that can affect the cowpea productivity, the Bemisia tabaci (Gennadius, 1889) biotype B stands out. The objective of this study was to evaluate the cowpea resistance associated to neem dosages at the whitefly development and oviposition. The experiments were conducted at a greenhouse at the Departamento de Fitossanidade of the Faculdade de Ciências Agrárias e Veterinárias, UNESP/Câmpus de Jaboticabal-SP, between october 2009 and August 2010, oviposition (chance and non-chance), antibiosis and neem oil ovicide action tests were performed. To identify the resistance types, seven Vigna unguiculata genotypes: BRS Milênio, BR17 Gurguéia, BR3 Tracuateua, BRS Novaera, Sempre Verde, BRS Urubuquara and IPA-206, were evaluated. According to obtained data, it can be concluded that the BRS Urubuquara, IPA-206 and BR17 Gurgueia presented non-preference for oviposition of B. tabaci biotype B resistance; the BRS Urubuquara genotype presented non-preference resistance for feeding and/or antibiosis; the Sempre Verde genotype was the more susceptible to infestation; and the B. tabaci biotype B prefers to ovipositate at the leaves abaxial faces of the upper cowpea plant position. After that, two resistant and one susceptible to whitefly infestation genotypes were selected. Those were then associated to a natural product with different neem oil dosages and non-preference for oviposition, antibiosis and ovicide action tests were then performed. According to obtained data it can be concluded that the BRS Urubuquara and IPA-206, associated or not to neem oil, were the less ovipositated by the B. tabaci biotype B; association between neem oil with the Sempre Verde genotype reduced the oviposition; the abaxial leaves faces of the upper cowpea plant position were the most affected by infestation at the Sempre Verde and IPA-206 genotypes; the neem oil provided...